Efficacy of different techniques for the release of Trichogramma chilonis Ishii, parasitising sugarcane internode borer, Chilo sacchariphagus indicus (Kapur).

摘要

Different techniques for the release of Trichogramma chilonis, namely ice-cream cup open/closed, plastic disposal cup open/closed, thermocool cup and loose egg exposure methods were compared with conventional release techniques involving tying of parasitized egg card by thread on to the leaf sheath or directly stapling the card on the lower ventral surface of middle leaf. The field trials were conducted during 1994-96 in Tamil Nadu. In the first season, release of the parasitoid through closed cupmethods (ice-cream cup and plastic disposal cup) and loose egg exposure procedure recorded higher emergence rates (70.8, 70.3 and 74.1%) than the conventional practice of card tying (61.0%) or card stapling (60.7%) to a sugarcane plant. A similar trend of parasitoid emergence was recorded in these release techniques during the following year. The increased emergence may be attributed to the safety afforded against sunlight, moisture, and natural enemies in modified techniques.